The objectives of the proposed research are: (a) to resolve the "promoter like" effects which are associated with the simple single point Oc mutation. This includes the continuation of the transcription studies on Lac mRNA lifetimes as a function of Oc mutation; (b) to obtain a deeper understanding of the E. coli Lac repressor-operator interaction thru a detailed analysis of double operator constitutive, Oc, mutations constructed from characterized single base substitution Oc mutations; (c) to investigate the operator translational possibility, in relationship to the very limited number of Oc types thus far obtained, which result in functional structural gene(s) products.